.head {
    background: url('C:\\vscodePro\\images\\bg.png') no-repeat center center #2C6CB6;
    padding-bottom: 19px;
}
.head .logo{
    float: left;
}
.head .logo img{

max-width: 100%;
}
   
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
.top {
    text-align: right;
    height: 41px;
    font-size: 14px;
    font-family: "Microsoft YaHei", sans-serif;
    font-weight: 400;
    color: #FFFFFF;
    background: #255C9B;
    line-height: 41px;
    padding-right: 20px;
}

nav {
    background-color: white;
    font-family: "Microsoft YaHei", sans-serif;
    
}
nav {
    background-color: white;
    font-family: "Microsoft YaHei", sans-serif;
    z-index: 100; 
}
nav ul {
    list-style: none;
    display: flex;  
    justify-content: center;
    margin: 0;
    padding: 0;
}
nav ul li {
    position: relative;
    padding: 10px 20px;
}
nav ul li a {
    color:black;
    text-decoration: none;
    font-size: 16px;
    font-family: Microsoft YaHei;
    font-weight: 400;
}
nav ul li ul {
    display: none;
    position: absolute;
    top: 100%;
    left: 50%; 
    transform: translateX(-50%); 
    background-color:rgba(44, 108, 182, .8);
    padding: 0;
    list-style: none;
    width: 160px;
    color: white;
    text-align: center; 
    line-height: 30px; 
}

nav ul li:hover ul {
    display: block;
}

nav ul li ul li {
    padding: 10px;
    text-align: center;
}

nav ul li ul li a {
    font-size: 14px;
    color: white
}
@media screen and (max-width: 768px) {
    nav ul {
        flex-direction: column;
        align-items: flex-start;
    }

    nav ul li {
        width: 100%;
        padding: 10px;
        text-align: left;
    }

    nav ul li ul {
        position: static;
        width: 100%;
        display: block;
    }

    nav ul li ul li {
        padding-left: 20px;
    }
}
nav {
    background-color: #ebebeb;
    position: relative; 
    z-index: 10; 
  }